Feminist blogger Louise Pennington says the new costumes are "not only sexist but utterly irresponsible".

"The women who play the pink and yellow Power Rangers are skilled athletes. Sexualising their outfits for a program aimed at children teaches young girls that their only value is in their appearance - regardless of their skill set and training," she tells The Huffington Post UK.

"Wedges will put the women at risk of ankle and knee injuries that their male counterparts won't experience. Equally, small girls emulating them are at a higher risk of injury."

On Twitter, dozens of other people have also expressed their disappointment in the clothing.

Caitlin Roper, a campaigner for women's rights group Collective Shout, says the outfits are part of a wider issue of sexism in the media.

"The choice of costuming here highlights a much prevalent trend in media, popular culture and real life, for women to be valued first and foremost for their physical appearance and sexuality," she tells us.

"Strength, intelligence and ability take a back seat to sexual appeal - particularly when ticket sales are involved."

Roper adds that having female characters in action roles, as opposed to being depicted as passive or weak, is a positive thing. But she questions why women "have to look hot" while kicking butt.

"It's interesting this trend to distinguish female action heroes from their male counterparts - the men are somehow the default and women have to be distinguished by emphasising and embellishing sexual characteristics and body parts in a way that doesn't happen to the men."